An Introduction to “Bugs” Whitney Cranshaw Colorado State University Arthropod Features • Segmented body • Exoskeleton • Jointed appendages • Bilateral symmetry of design • Dorsal heart/Ventral nerve cord Arthropod Characteristics Segmented bodies Phylum Arthropoda Arthropods Arthropod Characteristics External Skeleton Segmented bodies (Exoskeleton) Features of the Insect Exoskeleton Protection from: -Pathogens -Physical trauma -Insecticides, etc. Eleodes darkling beetles (aka “stink beetles”. “skunk beetles”, “circus beetles”) Primary advantage of an exoskeleton: Provides a means for small animals to avoid excessive water loss! Features of the Insect Exoskeleton Allows for development of: -Appendages Mobility is enhanced. Features of the Insect Exoskeleton Allows for development of: -Appendages -Specialized structures Enhance feeding, defense, movement Features of the Insect Exoskeleton Allows for development of: -Appendages -Specialized structures -Arthropod tracheal system of gas exchange Decreased water loss The exoskeleton allows for development of the arthropod tracheal system allowing transport/ exchange of oxygen to cells Spiracles The tracheal system transports oxygen to each cell Spiracle Disadvantage of an exoskeleton: 9:11 Darkening of a recently molted lady beetle adult 11:42 10:36 Soft Shell vs. Hard Shell Lobster Meat Extraction Trial July 2015 Meat Extraction Soft Shell vs. Hard Shell Soft shell Hard shell Water Component Soft Shell vs. Hard Shell Soft shell Hard shell Arthropod Characteristics Jointed appendages External Skeleton Segmented bodies (Exoskeleton) Arthropod Characteristic Body plan is bilaterally symmetrical Incorrect A Cricket’s Valentine I YOU Arthropod Features • Segmented body • Exoskeleton • Jointed appendages • Bilateral symmetry of design • Dorsal heart/Ventral nerve cord Classes of Arthropoda Arthropod Class Crustaceans Terrestrial Isopods* (Sowbugs and Pillbugs) *Subphylum Crustacea ; Class Malacostraca; Order Isopoda Crustacean Features • Two pair of antennae • Distinct head area • Body usually covered by a shield like carapace • Oxygen acquired through gills Seven pairs of legs Mouthparts Immature stages of sowbugs and pillbugs are similar in features as the adults, but smaller – a simple type of metamorphosis Sowbug Molting Front half molts first Back half molts second Molting occurs in two stages with the sowbugs and pillbugs Sowbugs and Pillbugs Sowbug Pillbug – also known as the ‘roly-poly’ Associated with moist areas and decaying vegetation Sowbugs Pillbug (a.k.a. “roly-poly’) Sowbugs Now if only I could roll into a ball… Pillbug Arthropod Class Diplopoda Millipedes Millipedes Two Pairs of Legs Per Segment Millipede Feature – Two pairs of legs per segment Duff Millipedes Arthropod Class Chilopoda Centipedes Centipedes 1 Pair Antennae 1 Pair Legs/ Body Segment Most centipedes have 15 to 23 pairs of legs Centipedes Head Pseudohead Maxillipeds Prey is captured with the maxillipeds and are injected with a toxin (cytolysin) Stone Centipede – A common garden resident House Centipede Orders of Arachnids Arachnid Feature – Two Body Regions Cephalothorax Abdomen Arachnid Feature – Four Pairs of Legs Chelicerae Pedipalps Photo courtesy of Brian Valentine Face of a longjawed spider showing chelicerae and pedipalps Spiders Order Araneae Some spiders use webbing to snare prey Some spiders hunt prey without the aid of silk Brian Valentine David Cappaert The Wood Louse Hunter/ Roly-Poly Killer Family Dysderidae ~Dysdera crocata Daddy longlegs, Harvestmen Order: Opiliones Mites & Ticks Order Acari Ticks feed on the blood of vertebrates Left: Before Below: After Scorpions Order Scorpiones Pedipalps (chelae) for prey capture Scorpion chelicerae (jaws) Scorpions fluoresce in ultraviolet light Scorpions fluorescing under black light An adorable baby scorpion! Common striped bark scorpion Centruroides vittatus Northern scorpion Scorpions of Western Colorado Photograph by Bob Hammon Northern desert hairy scorpion Windscorpions, Sunspiders, Solpugids Order Solifugae Photograph by Frank Peairs Photograph by Mike Gittleson Courtesy University of California The notorious “camel spider” photograph Orders of Insects Arthropod Characteristics Jointed External skeleton/ Appendages Exoskeleton Segmented Body Abdomen Thorax Head Insect body is organized into three regions Academy Award Nominee (1955) for Special Effects Special/Visual Effects Academy Award 1955 Nominee The movie 1917 2019 Winner won the award this year A Jerusalem cricket – an insect of unusual appearance found in western Colorado Thorax Abdomen Head Three pairs of legs – on the thorax Larvae of Lepidoptera, known as caterpillars, have 2-5 pairs of abdominal prolegs The prolegs are tipped with hook-like crochets Lepidoptera larvae (caterpillars) have prolegs on the abdomen Inchworms and loopers have only 2 or 3 pairs of prolegs Whitelined sphinx (Hyles lineata) – The common “hummingbird moth” of the western US Orders of Insects The Real Transformers - Insecticon How Many Kinds of Insects Are There on Earth? • Approximately 1 million different insect species have been described • It is estimated that there presently exist probably 4-6 million species of insects; some estimates are higher • New species of insects are described at a rate of about 7200/year Metamorphosis ‘Change in form’ A simple, or gradual pattern of metamorphosis Green peach aphid giving live birth to daughter Cannabis aphid mother and daughters (genetically identical) Mosquito Life Cycle Adult (left) Larvae/wrigglers (lower left) Pupae/tumblers (below) What Should We Cover? • Aphids • Japanese beetle • Hummingbird Moths • Scale insects • Whiteflies • Spider mites • Slugs • Gall insects • Earwigs • Nuisance invaders • Wood borers (incl. • Grasshoppers Emerald ash borer) • Codling Moth • Bark beetles/Ips • Flea beetles………. Next up: Natural Enemies of Insect Pests.